1. Field of the Invention
The present invention relates to low voltage electrical apparatus, more particularly, relates to fast closing mechanism for circuit breaker.
2. The Related Art
Regular motor protection circuit breakers or motor starters with a current level above 25 A are all operated by handles. When operated, the handle rotates in a forward direction means closing (switch on), and the handle rotates in a reverse direction means opening (switch off). Generally, such mechanisms have a fast opening structure because large break arc will be generated during an opening operation. However, many of the mechanisms do not have a fast closing structure, then large arc generated during a closing process may burn and damage the contacts, which may influence the life expectancy of the products.
Most of the mechanisms that are used today have a “slow closing and fast opening” structure, that is, the closing speed is very slow during a closing process. A slow closing process will result in a very large closing arc. According to a high-speed photography based calculation, the “slow closing and fast opening” structure needs a period from several hundreds milliseconds to one second to accomplish the closing process, such a long period may result in closing arc that would be large enough to damage the mechanism.